Enable Typescript noImplicitThis (#33250)

- Enable https://www.typescriptlang.org/tsconfig/#noImplicitThis
- Wrap Vue Template-Syntax SFCs in
[`defineComponent`](https://vuejs.org/api/general#definecomponent) which
makes type inference and linter work better
- Move `createApp` calls outside the SFCs into separate files
- Use [`PropType`](https://vuejs.org/api/utility-types#proptype-t) where
appropriate
- Some top-level component properties changed order as dictated by the
linter
- Fix all tsc and lint issues that popped up during these refactors

web_src/js/components/PullRequestMergeForm.vue

@@ -68,7 +68,7 @@ function toggleActionForm(show: boolean) {
   mergeMessageFieldValue.value = mergeStyleDetail.value.mergeMessageFieldText;
 }
 
-function switchMergeStyle(name, autoMerge = false) {
+function switchMergeStyle(name: string, autoMerge = false) {
   mergeStyle.value = name;
   autoMergeWhenSucceed.value = autoMerge;
 }